As with Marmot's enormously popular Zeus Jacket, the men's Zeus 1/2 Zip is a sweater-style, 800 fill power down wonder that packs into its own pocket, so it’s ready to bust out when the mercury plummets in town or on the trail. 800-fill goose down and a low profile design deliver astounding warmth with very little bulk, so it’s perfect underneath your favorite waterproof shell on chilly days.